using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;

namespace OA.Common.Encrypt
{ 
	/// <summary> 
	/// 加密
	/// </summary> 
    public class AES
    {
        //默认密钥向量
        private static byte[] Keys = { 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D, 0x79, 0x53, 0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F };

        private const int keylength = 32;

        private const string defaultKey = "nbvgjep@3547uhg9&_52lkm&p";

        /// <summary>
        /// 使用默认密钥加密
        /// </summary>
        /// <param name="encryptString">要加密的字符串</param>
        /// <returns></returns>
        public static string Encode(string encryptString)
        {
            return Encode(encryptString, defaultKey);
        }

        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="encryptString">要加密的字符串</param>
        /// <param name="encryptKey">加密密钥</param>
        /// <returns></returns>
        public static string Encode(string encryptString, string encryptKey)
        {         
            RijndaelManaged rijndaelProvider = new RijndaelManaged();
            encryptKey = MD5.MD5_32(encryptKey);
            rijndaelProvider.Key = Encoding.UTF8.GetBytes(encryptKey);
            rijndaelProvider.IV = Keys;
            ICryptoTransform rijndaelEncrypt = rijndaelProvider.CreateEncryptor();

            byte[] inputData = Encoding.UTF8.GetBytes(encryptString);
            byte[] encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData, 0, inputData.Length);

            return Convert.ToBase64String(encryptedData);
        }


        /// <summary>
        /// 默认密钥解密字符串
        /// </summary>
        /// <param name="decryptString">待解密的字符串</param>
        /// <returns></returns>
        public static string Decode(string decryptString)
        {
            return Decode(decryptString, defaultKey);
        }

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="decryptString">要解密的字符串</param>
        /// <param name="decryptKey">解密密钥</param>
        /// <returns></returns>
        public static string Decode(string decryptString, string decryptKey)
        {
            RijndaelManaged rijndaelProvider = new RijndaelManaged();
            decryptKey = MD5.MD5_32(decryptKey);
            rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey);
            rijndaelProvider.IV = Keys;
            ICryptoTransform rijndaelDecrypt = rijndaelProvider.CreateDecryptor();

            byte[] inputData = Convert.FromBase64String(decryptString);
            byte[] decryptedData = rijndaelDecrypt.TransformFinalBlock(inputData, 0, inputData.Length);

            return Encoding.UTF8.GetString(decryptedData);
        }

    }

	/// <summary> 
	/// 加密
	/// </summary> 
	public class DES
	{ 
		//默认密钥向量
		private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

        private const int keylength = 8;

        private const string defaultKey = "@3547uhg9&_52lkm&p";

        /// <summary>
        /// 使用默认密钥加密
        /// </summary>
        /// <param name="encryptString">待加密的字符串</param>
        /// <returns></returns>
        public static string Encode(string encryptString)
        {
            return Encode(encryptString, defaultKey);
        }

		/// <summary>
		/// DES加密字符串
		/// </summary>
		/// <param name="encryptString">待加密的字符串</param>
		/// <param name="encryptKey">加密密钥</param>
		/// <returns>加密成功返回加密后的字符串,失败返回源串</returns>
		public static string Encode(string encryptString, string encryptKey)
		{
            encryptKey = MD5.MD5_32(encryptKey).Substring(12, keylength);
            encryptKey = encryptKey.Substring(0, keylength);
            byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, keylength));
			byte[] rgbIV = Keys;
			byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
			DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
			MemoryStream mStream = new MemoryStream();
			CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
			cStream.Write(inputByteArray, 0, inputByteArray.Length);
			cStream.FlushFinalBlock();
			return Convert.ToBase64String(mStream.ToArray());
		
		}

        /// <summary>
        /// 默认密钥解密字符串
        /// </summary>
        /// <param name="decryptString">待解密的字符串</param>
        /// <returns></returns>
        public static string Decode(string decryptString)
        {
            return Decode(decryptString, defaultKey);
        }

		/// <summary>
		/// DES解密字符串
		/// </summary>
		/// <param name="decryptString">待解密的字符串</param>
		/// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>
		/// <returns>解密成功返回解密后的字符串,失败返源串</returns>
		public static string Decode(string decryptString, string decryptKey)
		{
			try
			{
                decryptKey = MD5.MD5_32(decryptKey).Substring(12, keylength);
                decryptKey = decryptKey.Substring(0, keylength);
				byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
				byte[] rgbIV = Keys;
				byte[] inputByteArray = Convert.FromBase64String(decryptString);
				DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
		
				MemoryStream mStream = new MemoryStream();
				CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
				cStream.Write(inputByteArray, 0, inputByteArray.Length);
				cStream.FlushFinalBlock();
				return Encoding.UTF8.GetString(mStream.ToArray());
			}
			catch
			{
				return "";
			}		
		}
	}


    #region ==========MD5=========
    public class MD5
    {
        public static string MD5_32(string Value)
        {
            string ret = "";
            System.Security.Cryptography.MD5CryptoServiceProvider md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
            Byte[] InBits = Encoding.GetEncoding("UTF-8").GetBytes(Value);
            Byte[] OutBits = md5.ComputeHash(InBits);
            for (int i = 0; i < OutBits.Length; i++)
            {
                ret += OutBits[i].ToString("x2");
            }
            ret = ret.ToUpper();
            return ret;
        }

        public static string MD5_16(string Value)
        {
            return MD5_32(Value).Substring(8, 16);
        }
    }
    #endregion
}